Allow users to specify connectors when configuring project monitors

[jamesagarside]

To enhance the capability of our GitOps Project Monitors offering it would be great if we could specify connectors on a per-monitor basis rather than all using the default connector.

Use Case

I have a customer who would like to offer service monitoring as a service enabled by customers making pull requests to a centralised repo. Each customer would want unique connectors, for example a group email for that customers team.

A basic implementation could look something like this.

import { journey, step, monitor, expect } from '@elastic/synthetics';

journey('www.example.com', ({ page, params }) => {
  // Only relevant for the push command to create
  // monitors in Kibana
  monitor.use({
    id: 'https://www.example.com/',
    schedule: 5,
    
    connector: "slack-dev-channel",

  });
  step('Go to https://www.example.com/', async () => {
    await page.goto('https://www.example.com/');
  });
});

To add more CI/CD functionality, customers could even specify an email address if connector type is SMTP, something like this:

import { journey, step, monitor, expect } from '@elastic/synthetics';

journey('www.example.com', ({ page, params }) => {
  // Only relevant for the push command to create
  // monitors in Kibana
  monitor.use({
    id: 'https://www.example.com/',
    schedule: 5,
    
    connector: "Elastic-Cloud-SMTP",
    emailTo: "joe.blogs@example.com",

  });
  step('Go to https://www.example.com/', async () => {
    await page.goto('https://www.example.com/');
  });
});